Air cleaner



April 29, 1952 w. G. RoMMEl. l 2,594,805

AIR CLEANERv Filed June 26, 1945 2 SHEETS--SHEET l S 2|' a i 3 'o n I0 Il l I 5 mi G f 1 F g g o 3 ,f..

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y l`\\ Q' n 'INI/ENTOR. wlLLl G. RoMMEL BY ATTORNEY April 29, 1952 w. G.RoMMEL 2,594,805

' AIR CLEANER Filed June 26, 1945 2 SHEETS-SHEET 2 INVENTOR. WILLIAM G.ROMMEL ATTORNEY Patented Apr. 29, 1952 William G. Rommel, Playa Del Rey,Calif., as-

signor to The Garrett Corporation, Airesearch Manufacturing Companydivision, Los Angeles, Calif., a corporation of California ApplicationJune 26, 1945, Serial No. 601,667

(ol. 18s- 7) 6 Claims.

My invention relates in general to air cleaners and relates inparticular to a simplied air cleaner wherein dust particles, smoke, mistand water may be removed from a flow of air or other gaseous fluid.

It is an object of the invention to provide an air cleaner which may beinstalled in a duct through which a ow of air is passing toward a pointof utilization, this air cleaner being especially suitable for use onaircraft cabins in conjunction with the cabin pressurizing and airconditioning systems because of its light Weight and compact form.

It is an object of the invention to provide an air cleaner wherein partsare cooperatively arranged so as to accomplish in a relatively shortdistance of air iiow an eiective removal from the air flow ofcontaminating particles. l

A further object of the invention is to provide an air cleanerrhaving anenclosure or a housing defining a path of fiow for the air to be cleanedwith a simple means for producing a swirling of the air ow as it movestoward the outlet of the device, and impressing electro-potential on theparticles carried by the air in such effective manner that theseparticles will be repelled outwardly from the positively chargedelectrodes of the device toward a negatively charged wall which liesalong or around the path of flow, these particles passing through anannular mouth into a receptacle or collector as a result of theapplication of electrostatic and centrifugal forces to the particles.

A further object of the invention is to provide in an electrostatic aircleaner or separator, two separate positively charged electrodes orpoles, one of these electrodes being centralized with respect to thepath of iiow through the device and the other of the electrodes beingmarginal, so called for the reason that it extends toward the margin ofthe path of ow.

An object of the invention is to provide in a device of this characterpositively charged electrodes such as described in the precedingparagraph, the centralized electrode being positioned downstream fromthe marginal electrode and being maintained at a higher electricalpotential than the marginal electrode.

A further object of the invention is to provide a simple Yformofconstruction wherein varies are supported in the path of iiow of the airin insulated relation to the` shell or enclosure of the device, thesevanes being formed of metal so as to serve as electrodes or poles andbeing shaped and positioned so as to cause the air which passes the sameto sw-irl rapidly. In the device I have shown a fan acting to producemovement of air from the inlet to the outlet. This fan may or may not beused when the device is installed in an air duct through which there isan established flow of air. Where the fan is used under such conditions,it assists in maintaining a desired velocity of air now.

Further objects and advantages of the invention will be brought out inthe following parts of the specification.

Referring to the drawings which are for illustrative purposes only:

Figure 1 is a sectional view showing a preferred embodiment of myinvention;

`Figure 2 is a cross section taken as indicated by the line 2-2 ofFigurel; and

Figure 3 is across section taken as indicated 'by the line 3--3 ofFigure l.`

As shown in Figure 1, the device employs an enclosure or shell I0 whichis most conveniently made in tubular or cylindric form so that it may beconnected between consecutive portions of an air duct leading toV achamber, such as an aircraft cabin which is to receive the cleaned andconditioned air. Theshell II) has three axially aligned sections II, I2and I3. Section Il is a metal tube and therein, by means of radial armsI4, a motor I5 is supported in a position to drive a fan I6 capable ofproducing a rapid movement of air from the inlet Il of the device to itsoutlet I8. 4

The intermediate section I2 of the shell h comprises an inner shortcylinder Iii of insulating material having an internal diameter veryslightly smaller than the internal diameters of the sections Il and I 3.In the outer cylindric face of the member I 9 there is a shallow channel20 which receives a metal ring 2l covered by a thin cylinder 22 ofinsulating material. in the practice of the invention, the cylinders ISand 22 may be 'both made from Bakelite.

A plurality of metal vanes 23 are secured within the cylinder I9 bymetal rivets 2li which extend through flanges 25 formed on the vanes 23,through openings in the cylinder IQ and in the metal ring 2|, theserivets therefore providing an electrical connection between the ring 2Iand the vanes. The vanes 23 are curved as shown in Figure 1 and extendfrom near the axis of the shell I0 toward and preferably to the marginof the path of flow of air, dened by the inner surface of the member I9.

The air impelled forwardly by the fan I6, or by other means. asindicated by the arrow 26, passes through the electrication zone definedby section I2, and in passing through section l2 the flow of air isacted on by the vanes, causing the same to swirl rapidly as indicated byarrows 21.

The section I3 comprises a metal cylinder 28 connected at its front endto the cylindrical member I9 and having at its rightward or downstreamend an out-turned lip 29. The outlet i8 of the device is formed by arelatively short cylinder 30, smaller in diameter than the cylinder 28and being positioned so that its leftward end or annular edge 3l willproject a short distance into the rightward end of the cylinder 28,thereby forming between the overlapping wall portions of the cylinder 28and the cylinder 33 an annular mouth 32 which is faced upstream oragainst the flow of air which is traveling through the device. Aroundthe rightward end of the cylinder 28 and in communication with the mouth32 there is an annular collecting chamber 33 comprising a wall 34 whichregarded in cross section as in Figure l is curved outwardly from theleftwardportion of the cylinder 28 and is then reversely curved as shownat 35 so as to extend around the lip 23, in spaced relation thereto, toengage the cylinder 38 adjacent its inner edge 3l. In the lower part ofthe wall 34 of the collector 33 there is an outlet opening 36 which,when the device is employed in an aircraft, may be connected throughsuitable piping with the exterior, or which may be connected as shownwith a receptacle 31 in which the removed particles may accumulate. Airmay escape from the receptacle through small openings 3'la spacedupwardly from the bottom of said receptacle. The air will escape ratherslowly from the receptacle and the dust or other foreign particlesentrained in the air stream will collect in the bottom portion of thereceptacle. Also, the air flowing through the conduit or shell l0 movesrelatively slower therethrough so that the device works very effectivelyin separating and cooling foreign particles entrained in the air stream.

An electrode body 38 formed as a ball is positioned near or preferablyupon the axis of the path of flow of air toward the outlet I8. This ballis of metal and is situated on the inner end of a metallic post 38 whichextends through the wall of the cylinder 28 to the exterior for thepurpose of external electrical connection. This post 33 is fullyinsulated from the cylinder 28 by insulators 38 and lll. The ball 38 isdisposed between the vanes 23 and collector 33, but is preferably closerto the vanes 23 than to the mouth 32 of the collector 33.

As further shown in Figure l, a screw i2 is provided as a terminal formaking electrical connection with the vanes 23, this screw passingthrough the flange 25 of one of the vanes 23 and through the ring 2l tothe exterior. A power source 43 is provided having positive terminals 44and 45 and a negative terminal 48, the terminals 44 and 45 beingconnected respectively to the screw 42 and to the post 39. The terminal48 is grounded to the housing of the electric power unit which isgrounded, as at 46a, while the terminal 4Gb is connected to the cylinder28. the latter being grounded at 46c so that the terminal 46 isconnected to the metal cylinder 28 through the ground and said cylinderis at ground potential. The power source 43 is capable of producing ahigh potential difference between its positive electrodes 23 and 38 andits negative electrode or pole formed by the cylinder 28. The potentialapplied to the ball 38, however, is greater than the potential impressedupon the vanes 23, so that the greatest potential difference existsbetween the ball 38 and the cylinder 28.

In the operation of the device the centrifugal action resulting from theswirling of the air flow between vanes 23 carries heavier dust particlesoutward toward the cylinder 28, and this swirling action will have alesser centrifugal effect upon the smaller particles entrained in theair liow in keeping with the masses of these respective smallerparticles. However, the particles become positively charged in theirpassage through the section l2, due to their engagement with or movementin close proximity to the electrodes lformed by the vanes 23.Accordingly, these .charged particles. as they pass toward the outletI8, are brought under the influence of the electrostatic eld existingbetween the ball 38 and the cylinder 28 and since they are positivelycharged, the particles will be repelled by. the ball electrode 38 andattracted to the cylinder 28 with the result that they will travel alongthe surface of the cylinder 28 and through the mouth 32 into thecollector 33.

I claim: l

1. In a device for separating particles from a fluid stream, thecombination of: an electronegatively charged cylindrical wall dening aduct through which the fluid stream is adapted to ow. said duct havingan inlet and an outlet; an annulus of insulating material spaced fromsaid outlet; vanes projecting from said annulus toward the axis of thepath of flow of said fluid stream, said vanes being shaped so as toswirl the fluid as it passes toward said outlet; means for impressing apositive potential on said vanes; a ball electrode; means extendinginwardly from said wall for supporting said ball electrode near the axisof said path of flow and downstream from said vanes; means forimpressing on said ball electrode a positive electro-potential greaterthan the potential impressed on said vanes; and a collector disposed insaid path of flow between said negatively charged wall and said outlet.

2. In a device for separating particles from a fluid stream, thecombination of an electro-negatively charged conduit dening a path offlow for said fluid stream, said conduit having an inlet and an outlet;an annulus of insulating material spaced upstream from said outlet;vanes projecting from said annulus toward the axis of said path of flow,said vanes being shaped so as to swirl the fluid as it passes towardsaid outlet; means for impressing a positive potential on said vanes; aball electrode; means extending into said conduit for supporting saidball electrode near the axis of said path of flow and downstream fromsaid vanes; means for impressing on said ball electrode a positiveelectro-potential greater than the potential impressed on said vanes; atubular member forming an upstream facing lip in said path of flowadjacent said outlet to form a collector mouth adjacent the periphery ofsaid stream; and means forming a collecting chamber externally of saidconduit and communicating with said mouth.

3. In a device for separating particles from a fluid stream, thecombination of: an electronegatively charged cylindrical wall defining aduct through which the fluid stream is adapted to flow, said duct havingan inlet and an outlet; an annulus of insulating material spaced fromsaid outlet; vanes projecting from said annulus toward the axis of thepath of ow of said fluid stream, said vanes being shaped so as to swirlthe fluid as it passes toward said outlet; means for impressing apositive potential on said vanes; a ball electrode; means extendinginwardly from said wall for supporting said ball electrode near the axisof said path of flow and downstream from said vanes; and means forimpressing on said ball electrode a positive electro-potential greaterthan the potential impressed on said vanes.

4. In a device for separating particles from a fluid stream, thecombination of: an electro-negatively charged conduit dening a path ofow for said uid stream, said conduit having an inlet and an outlet; anannulus of insulating material spaced upstream from said outlet; vanesprojecting from said annulus toward the axis of said path of flow, saidvanes being shaped so as to swirl the fluid as it passes toward saidoutlet; means for impressing a positive potential on said vanes; a ballelectrode; means extending into said conduit for supporting said ballelectrode near the axis of said path of now and downstream from saidvanes; means for impressing on said ball electrode a positiveelectro-potential greater than the potential impressed on said vanes;and a tubular member forming an upstream facing lip in said path of owadjacent said outlet to form a collector mouth adjacent the periphery ofsaid stream.

5. In a device for separating particles from a. uid stream: a straightelectrically charged conduit defining a path of ilow for said fluidstream. said conduit being disposed horizontally and having an inlet andan outlet; means for inducing a swirling movement to the iluid of saidstream as it moves through said conduit; means for impressing anelectric charge on said swirling means, said charge being of oppositesign from that of the wall of the conduit; electrode means in said fluidstream located between said swirling means and said outlet; means forimpressing an electric charge on said electrode, said charge being ofhigher potential than that on the swirling means and of the same sign,said electrode means being so located that particles entraned in the uidwill pass between same and the electrically charged wall; and collectingmeans disposed so as to collect particles separated from the iluidstream by the electrically charged means.

6. In a device for separating particles from a fluid stream, thecombination of: an electronegatively charged cylindrical wall dening aduct through which the uid stream is adapted to flow, said duct havingan inlet and an outlet; an annulus of insulating material spaced fromsaid outlet; vanes projecting from said annulus toward the axis of thepath of now of said uid stream, said vanes being shaped so as to swirlthe uid as it passes toward said outlet; means for impressing a positivepotential on said vanes; a ball electrode; means extending inwardly fromsaid wall for supporting said ball electrode near the axis of said pathof flow and downstream from said vanes; means for impressing on saidball electrode a positive electro-potential greater than the potentialimpressed on said vanes; and collector means disposed in said path of owbetween the negatively charged wall and said outlet, said collectormeans including a collecting receptacle having bleed means therein forthe bleeding of air from said receptacle.

WILLIAM G. ROMMEL.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 1,371,995 Nesbit Mar. 15, 19211,381,719 McGee et al. June 14, 1921 1,440,887 Nesbit Jan. 2, 19232,101,168 Deutsch Dec. 7, 1937 FOREIGN PATENTS Number Country Date83,440 Austria Apr. 13, 1921 425,039 Germany Feb. 11, 1926 562,893Germany Nov, 2, 1932

